| ; Test that the backend does not mess up the I/R in case of a use of an undef | |
| ; register. This typically happens while expanding a pseudo or otherwise | |
| ; replacing an instruction for another. | |
| ; | |
| ; RUN: llc < %s -mtriple=s390x-linux-gnu -mcpu=z13 -verify-machineinstrs | FileCheck %s | |
| ; LLCRMux | |
| define void @f1(ptr) { | |
| ; CHECK-LABEL: f1: | |
| ; CHECK-NOT: *** Bad machine code: Using an undefined physical register *** | |
| BB: | |
| %L5 = load i8, ptr %0 | |
| %B9 = lshr i8 %L5, -1 | |
| br label %CF | |
| CF: ; preds = %CF, %BB | |
| %Cmp25 = icmp ne i8 27, %B9 | |
| br i1 %Cmp25, label %CF, label %CF34 | |
| CF34: ; preds = %CF | |
| ret void | |
| } |